Method of making duplicating forms



Feb. 5, 1935. O wlLHELM 1,990,106

METHOD OF MAKING DUPLICATING, FORMS Filed Dec. 26, 1933 A B C D I flsfldaufi I U .T .fdA El /n ventol:

0. l l i/ /m Patented Feb. 5, 1935 METHOD F MAKING DUPLKCATING FORMS Ottmar Wilhelm, Heidelberg, Germany Application December 26, 1933, Serial No. 703,989 In Germany November 17, 1932 1 Claim.

The known duplicating forms have hitherto been made by applying the duplicating ink on the back of the paper by spreading or printing or by unrolling from a figured immersion roller.

When'the ink is spread on, a layer of very uniform thickness is obtained, but it is not possible to obtain sharp edges to the parts covered with ink.

In order when spreading on the ink to obtain sharp edged areas of ink, brushes have been provided within a cylinder, the wall of which has stencil-like apertures.

edges is, however, still possible since the duplicating ink is spread from the brushes onto the :3 edges of the stencil before these are pressed onto the paper web during the rolling of the cylinder.

When the ink is printedon, on the other hand,

it is possible to obtain sharply defined areas and symbols. The ink layer, however, has not the uniformity and thickness of a layer made by spreading on. This lower uniformity is especially disadvantageous when it is desired to transfer small letters and symbols by the duplicating process.

It is already known to apply the separate components of an ink layer individually or mixed together in groups on carbon paper. By this means an extended uniformity in the removal of ink was to be obtained. More particularly the uppermost layer of the covering should be free of pigment material in order to prevent removal of ink when touching the paper. apply a subsequent protective layer of colophony or wax to a single copying ink layer.

According to the invention the drawbacks of the known method are avoided by first printing the copying ink onto the appropriate parts of the paper and then applying a further ink layer on the same place by spreading.

It is also possible to print signs or symbols with duplicating ink on certain parts of the paper in order to be able to transfer them later'by simply rubbing with the finger nail or'the like, and to provide other parts of the paper intended for transferring writing with a combined application of' duplicating ink by printing and spread- This method can also be employed for applying the known multi layer ink coatings.

In the accompanying drawing Fig. 1 shows diagrammatically a device for carrying out the method. Figs. 2 and 3 show the front and rear sides of a duplicating form which according to the tial ink layer.

The smudging of the.

her in order to soften the duplicating ink which It is also known to- From the roller 1 a paper web 2 passes into a rotary printing machine, in which it is provided with a preliminary impression in the printing mechanism 3, 4. From the printing mechanism 3 the paper web runs directly to a further printa ing mechanism employed for applying duplicating ink. The application of ink is effected between the two cylinders 5 and 6, the cylinder 6 serving as ink carrier and the cylinder 5 as pressure cylinder. The-cylinder. 6 is constructed asa form plate cylinder andis provided with ink from the container 7 through a suitable number of distributing rollers. Both the cylinder 6 and the ink container '1 are heated in a known man- 15 is solid at ordinary temperatures. The cylinder 5, on the other hand, may be-cooled in order to cause' the ink to set immediately after it is applied.

The paper web which is printed with ink between the cylinders 5 and 6 then passes to a cylinder 8 which receives its ink'covering also from the ink container 7 or from a separate container. In order to produce a subsequent coating of the ink layer printed on between the cylinders 5 and 6, the cylinder 8, since it runs with the same speed as the printing cylinder 6, is constructed as a so-called expansion cylinder. With this it v is possible, even during the running of the machine, to alter the circumference of the cylinder within narrow limits. By this means the result is obtained that the surface of the cylinder performs a slipping movement with respect to the paper web which runs with the peripheral speed, of the printing cylinder 6.

In order, for example, to coat a surface which is already provided with an ink printing having sharp edges, the cylinder 8 is so adjusted thatthe'form plate secured thereto touches the paper just behind thesharp edge of the first impressionI The form plate, on account of the circumference' of the cylinder 8 being, for example, somewhat enlarged, performs a slipping movement over the first impression until the edge of the plate reaches a point just in front 'of the second edge of the previously printed ink layer. The finished ink coating then consists of two superposed ink layersof which the lower printed on layer is a little larger than the layer spread thereover. At the edges of the coating it consists of a single printed ink layer with sharp edges.

The cylinder 8 also can be heated in a known manner. The paper web runs after the secand application of ink over a cylinder 9, which, 55

like the cylinder 5, may be cooled. It then passes as required into a cutting or folding device.

If a form is to have applied on its rear side, for example, a partial covering of duplicating ink and some separate symbols, between the cylinders 5, 6 the separate symbols 10 (Fig. 3) as well as an inscription 11 are printed on, and at the. same time the'parts of the paper which are hatched in the drawing are printed with duplicating ink. As the paper web runs over the cylinder 8, only the shaded parts are spread with a further application of ink.

In the same manner as is known from the manufacture of ordinary duplicating forms, theber cylinder which receives itsimpression from a form plate cylinder placed in front. In this way the preliminary printing is applied at the same time as the duplicating ink.

For printing and spreading, as mentioned above, form plates are employed which are arranged on the various cylinders. These form plates may have a finer or coarser screen so that according to the requirement a finer or thicker ink deposit is obtained.

What I claim is:

A method of making duplicating forms consisting in applying a double coating of duplicating ink over at least a part of the back of the preliminarily printed form, the first coating of ink being applied by a printing process, and the second coating being applied on top of the first coating by means of a spreading operation.

O'I'I'MAR WILI-IEIM. 

